chore: import upstream snapshot with attribution

src/array/cpu/array_repeat.cc

@@ -0,0 +1,51 @@
+/**
+ *  Copyright (c) 2020 by Contributors
+ * @file array/cpu/array_repeat.cc
+ * @brief Array repeat CPU implementation
+ */
+#include <dgl/array.h>
+
+#include <algorithm>
+
+namespace dgl {
+using runtime::NDArray;
+namespace aten {
+namespace impl {
+
+template <DGLDeviceType XPU, typename DType, typename IdType>
+NDArray Repeat(NDArray array, IdArray repeats) {
+  CHECK(array->shape[0] == repeats->shape[0])
+      << "shape of array and repeats mismatch";
+
+  const int64_t len = array->shape[0];
+  const DType *array_data = static_cast<DType *>(array->data);
+  const IdType *repeats_data = static_cast<IdType *>(repeats->data);
+
+  IdType num_elements = 0;
+  for (int64_t i = 0; i < len; ++i) num_elements += repeats_data[i];
+
+  NDArray result = NDArray::Empty({num_elements}, array->dtype, array->ctx);
+  DType *result_data = static_cast<DType *>(result->data);
+  IdType curr = 0;
+  for (int64_t i = 0; i < len; ++i) {
+    std::fill(
+        result_data + curr, result_data + curr + repeats_data[i],
+        array_data[i]);
+    curr += repeats_data[i];
+  }
+
+  return result;
+}
+
+template NDArray Repeat<kDGLCPU, int32_t, int32_t>(NDArray, IdArray);
+template NDArray Repeat<kDGLCPU, int64_t, int32_t>(NDArray, IdArray);
+template NDArray Repeat<kDGLCPU, float, int32_t>(NDArray, IdArray);
+template NDArray Repeat<kDGLCPU, double, int32_t>(NDArray, IdArray);
+template NDArray Repeat<kDGLCPU, int32_t, int64_t>(NDArray, IdArray);
+template NDArray Repeat<kDGLCPU, int64_t, int64_t>(NDArray, IdArray);
+template NDArray Repeat<kDGLCPU, float, int64_t>(NDArray, IdArray);
+template NDArray Repeat<kDGLCPU, double, int64_t>(NDArray, IdArray);
+
+};  // namespace impl
+};  // namespace aten
+};  // namespace dgl